The \(\epsilon \) -indicator has been found to have a better performance in maintaining convergence, so SRA3 choose the quality indicator \(I_{\epsilon +}\)  as the selection principle for CA with reference to IBEA and SRA [1]}, [2]}. The indicator \(I_{\epsilon +}\)  measures the minimal distance that a solution should be translated in each dimension to weakly Pareto dominate the other solution [3]}, which is shown by equation (1). Then we refer to the IBEA's approach to calculate the individual fitness as shown in equation (2).
\(I_{\epsilon +}(x,y)=min_\epsilon (f_i(x)-\epsilon \le {f_i(y)},i\in \lbrace 1,2,\dots ,m\rbrace )\) 
\(I_1(x)=\sum _{y\in {P},y\ne {x}}-e^{-I_{\epsilon +}(y,x)/k}\) 
